Approximately 50% of patients with pancreatic cancer develop severe pain. Additionally, anxiety and depression are more common in cancer patients with severe pain.
Although 90% of patients with cancer obtain relief with oral analgesics, pain is the aspect of cancer that is most feared.
Pancreatic cancer results in pain because the pancreas is near the liver, stomach, duodenum, jejunum, and transverse colon. Pain, from pancreatic cancer, may also be felt at distant sites because the pancreas is innervated (supplied) by nerves from the parasympathetic and sympathetic nervous systems. Pain may occur in the upper, central aspect of the abdomen (mid epigastric and left epigastric) and in the left rib cage (intercostal space). Pancreatic cancer commonly spreads to the liver which results in pain in the right upper aspect of the abdomen. There can also be pain referred to the right shoulder or neck without tumor invasion of these areas. This is due to the complex nerve supply (innervation) of the pancreas and neighboring structures.
Medications for pain secondary to pancreatic cancer include opioids, antidepressants, anticonvulsants, non-steroidal anti-inflammatory drugs (NSAIDs), acetaminophen (Tylenol) and corticosteroids. Sometimes, medicines called adjuvant analgesics are also used. These are medicines used for purposes other than the treatment of pain but which are effective in relieving pain sometimes. These can be prescribed by oncologists, pain management specialists and primary care physicians. As the illness progresses, around the clock opioid dosing with rescue doses will be needed. Opioids on a timed, regular basis, along with opioids on an "as needed" basis are prescribed. Pain medications taken round-the-clock are more effective and may decrease the total daily amount of pain medication required. This is a successful method for treating patients with significant pain. Opioids can be given orally, topically or even rectally on an outpatient basis. They can also be administered subcutaneously or intravenously on an inpatient basis.
Early side effects of opioid medication include nausea, sedation, and respiratory depression. Patients usually become tolerant to these three side effects. Unfortunately, constipation is a side effect with which tolerance does not occur. Aggressive preventive measures to avoid constipation will be needed, and this should be discussed with your doctor.
A celiac plexus nerve block can be used with medication management. Rare complications include paraplegia, pneumothorax, and gangrene of the bowel. Respiratory depression may occur if the pain relief is quick and dramatic and the patient is on high doses of opioids. The celiac plexus nerve block should be performed with CT scan (computerized tomography) guidance.
For severe abdominal pain, secondary to pancreatic cancer, intraspinal drug delivery can also be effective. This can be delivered in either the intrathecal or epidural spaces. For a permanent intraspinal drug delivery system, the intrathecal space is used, while the epidural space is a temporary measure.
Newer treatment options are available. Thorascopic splanchnicectomy is a minimally invasive procedure that cuts specific nerve branches. This procedure is done under general anesthesia.
Pain may also be treated when surgery for pancreatic cancer is performed. If a patient cannot have surgery for cure but has exploration with or without palliative bowel bypass procedure(s), an alcohol nerve block may be performed. Alcohol is injected directly on both sides of the nerve root that runs behind the pancreas, the celiac plexus. This can diminish pain related to tumor growth by numbing the nerves for approximately 3 to 4 months. Diarrhea is common after procedures performed on the celiac plexus.
Non-drug therapies may also be helpful in treating the pain from pancreatic cancer and improving the patient's ability to perform activities of daily living. Examples include adopting coping skills, massage, hypnosis, relaxation, counseling, imagery, distraction, heat and cold therapy, physical therapy, and emotional support. More than one non-drug pain therapy can be used at any one time with pain medications.
Radiotherapy is occasionally used to decrease pain in pancreatic cancer. Although controlled, randomized trials have not been performed, radiotherapy is occasionally used combined with celiac plexus nerve blocks and/or opioids with the other treatment modalities described above.
Jose Veliz MD is the medical director of Palomar Spine & Pain, in Escondido, CA (North San Diego County).